Suspension system for multiwalled containers

ABSTRACT

Disclosed is a system for suspending the inner vessel of multiwalled containers such as used for storing cryogenic fluids. The suspension system is characterized in that elongate members are used to hold the inner vessel in pure tension so that the inner vessel can expand or contract without changing the load on any of the support members. There is also provided locking means to rigidly secure the inner vessel from movement during transport of the container.

United States Patent Hornbeck [4 1 Sept. 19, 1972 [5 SUSPENSION SYSTEM FOR MULTI- 2,926,810 3/1960 Yeager ..220/15 WALLED CONTAINERS 3,021,027 2/ 1962 Claxton ..220/15 72 I t 2 Cl H 3,078,004 2/1963 Randolph ..220/ 15 X 1 f J wemsvne 3,163,313 12/1964 Reynolds et al. ....220/9 LG x 3,207,353 9/1965 Canty et al. ..220/15 Asslgnw Air Products and Chemicals, 3,251,501 5/1966 Mesnager ..220/15 Allentown, 3,446,388 5/1969 Greenberg ..220/15 [22] Filed: Sept. 2, 1969 M E J hR L l mary xammerosep ec arr [21] Appl' 854,364 Assistant Examiner-James R. Garrett Attorney-Ronald B. Sherer, James C. Simmons and 52 us. c1. ..220/15 Max Klevit [51] Int. Cl. ..B65d 25/00 [58] Field 01 Search ..220/15, 9 LG, 9 D, 10 ABSTRACT Disclosed is a system for suspending the inner vessel [56] Reierences C'ted of multi-walled containers such as used for storing UNITED STATES PATENTS cryogenic fluids. The suspension system is charactenzed in that elongate members are used to hold the 2,587,204 2/1952 Patch, Jr. et al. ..220/15 X inner vessel in pure tension so that the inner vessel v Palvanas ct X can expand or contract without the load on 3,331,525 7/1967 Coehn ..220/15 any of the support members There i also provided locking means to rigidly secure the inner vessel from r t th 2,643,022 6/1953 Cornell ..220/15 movement durmg of e comm 2,858,136 10/1958 Rind ..220/15 X 3 Claims, 2 Drawing Figures H l L... "E. 1

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l 2 I634 ,1 i i l I i l 62 g l 36' Murrow 19 1912 m b mm J w H e r m C ATTORNEY SUSPENSION SYSTEM FOR MULTI-WALLED CONTAINERS BACKGROUND OF THE INVENTION This invention pertains to the means for supporting the inner vessel of a multi-walled container such as useable for storing liquefied gases. In particular, the invention pertains to inner vessels supported by thin elongated suspension members such as disclosed in US. Pat. Nos. 2,926,810 and 3,163,313.

The foregoing patents disclose using thin elongated rods to suspend the inner vessel of a multi-walled container. The rods are used to restrain the'inner vessel and are sized so that expansion or contraction of the inner vessel causing varying loads on the suspension members do not cause the suspension members to fail. This necessitates over designing suspension members since the loads caused by temperature changes are in addition to those required to support the inner vessel.

The novel suspension system, according to the present invention, overcomes the difficulties of the prior art in that thin elongated suspension members are used to support the inner vessel. The support system is arranged so that only tension loads of predetermined levels are placed on any one of the support members. Only one end of the inner vessel, according to the present invention, is completely restrained so that size changes of the inner vessel do not change the load configurations on any of the individual support members.

SUMMARY OF THE INVENTION The present invention comprises using thin elongated structural members to support the inner vessel of a multi-walled container. One end of the inner vessel is restrained and the other end of the inner vessel is supported in such a manner as to be free to move relative to the restrained end. The support mechanism is designed so that only tension loading of the elongated support members is achieved. There is also provided removable restraining devices so the container can be shipped via conventional carriers without damage to the inner vessel. The restraining members can be readily removed when the container reaches its destination.

Therefore, it is the primary object of this invention to provide an improved suspension system for the inner vessel of a multi-walled container.

It is another object of the present invention to provide an inner vessel support system for a multi-walled container wherein conduction losses through the support members are held to a minimum.

It is still another object of the present invention to provide a suspension system for the inner vessel of a multi-walled container wherein the loads on the suspension system are not materially changed by changes in temperature of the inner vessel.

It is a further object of this invention to provide a multi-walled container with temporary restraining devices for restraining the inner vessel during shipment of the multi-walled container.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a sectional view taken along line 1-1 of FIG. 2 showing a multi-walled container according to the present invention.

FIG. 2 is a view taken along line 2-2 of FIG. 1.

LII

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing there is shown in FIG. 1 a multi-walled storage vessel 10 comprising an outer vessel 12 and inner vessel 14 and disposed therebetween a radiation shield 16. The particular embodiment shown in FIG. 1 has reference to a storage vessel for a very low boiling point liquefied gas such as helium. However, the apparatus of the invention is applicable to other types of multi-walled storage vessels. The outer vessel 12 contains supports 18 and 20 for supporting the container 10 in a horizontal position. Vessel 10 has a pair of dished heads 22, 24 with access ways 26 and 28. The access ways (manway) 26, 28 are provided with closure means 30, 32 for sealing of the outer vessel 12 after onsite installation of the container is complete. Such devices are known in the art.

The inner vessel 14 is provided with a pair of dished heads 34 and 36 with support mounting means 38, 40. The support mounting means 38 and 40 are adapted to receive the inner vessel suspension members shown as 42, 44 associated with head 34 (FIG. 2) and 46 being only one of a pair mounted similarly to 42, 44 shown in FIG. 2, for head 36. The suspension members 42, 44, 46 comprise a pair of thin elongated structural elements 48, 50 pivotably connected to outer vessel 12 as shown in reference to support member 42 in FIG. 2. The purpose of the pivotal connection on either end of all support members is to prevent bending stresses on the supports as the inner vessel changes size with temperature changes. The structural members 48, 50 are readily fabricated from plates of stainless steel or other structural materials. The structural members 48, 50 are passed through the radiation shield 16 and pivotably connected to a suitable receiving member 52 on the inner wall of the outer vessel 12. The supports 42, 44, 46 are pivotably connected to the inner vessel at 38 and 40 respectively. Associated with the support members 42, 44, 46 are suitable insulating members 54, 56, and 58 tothermally insulate the support members from the radiation shield. Such insulation members can comprise insulating materials such as fiberglass, mats, aluminized mylar, or polyurethane foam.

At one end of the inner vessel 14 there are provided two additional support members shown generally as 60, 62 in FIG. 2. The support members 60, 62 are of a similar construction to members 42, 44, 46 and are used to rigidly fix the end of inner vessel 14 containing head 34. It is shown in the drawings that the left end of the inner vessel 14 is restrained; however, either end can be restrained without departing from the teaching of the present invention.

It will be appreciated that when the container is assembled in the manner provided, the inner vessel 14 is suspended under pure tension loads on the support members 42, 44, 46, 60 and 62. It will be further appreciated that there is a second support member supporting end 36 of inner vessel 14 and that the support members are fastened so that they can move relative to the fixed end of vessel 14 and placed in identical configuration to those shown in FIG. 2 so that the inner vessel 14 is supported by four members in tension. Members 60 and 62 are then added to restrain one end of inner vessel 14 by applying a tension load to members 60, 62. The inner vessel 14 suspended in this manner allows for movement of said inner vessel 14 due to temperature changes caused by the addition or removal of the cryogenic fluid from the inner vessel. Such size changes in the inner vessel causes the freely movable end (36) of the inner vessel 14 and its associated supports to move relative to the fixed end (34) of vessel 14 because the supports associated with head 36 are pivoted to allow movement thereof. Therefore, it will be appreciated that the size changes do not induce loads on the support members other than those caused by the weight of the inner vessel 14 and the cryogenic fluid addedthereto. Such loads are pure tension loads readily predictable and not subject to change. Therefore, the support system can be designed up to the safe working stress of the structural material and the heat leak due to conduction can be predicted and vthereby minimized by selecting the proper size and composition of the support members. The structural .members are elongated thereby helping to decrease heat losses since the heat loss varies directly with crosssectional area and inversely with length of the support members.

Shown in the drawing are additional temporary supports or restraining members 64 and 66. Support members 64 and 66 are adapted to restrain movement of the inner vessel 14 during shipment of the container. There is provided on either end of vessel 14 a suitable connecting device such as a flange with a threaded aperture to receive the bottom threaded end of the support 64 and 66. There are provided apertures, such as 68 (FIG. 2) in the radiation shield 16 for passage of the support members therethrough. There is further provided on the vessel 12 cover plates 67 and 69 to receive the opposite end of members 64, 66 to be secured to the vessel 12. Supports 64, 66 are made to be engaged in a socket or receiving recess in members 38, 40 respectively and to protrude above cover plates 67, 69 so that cover plates'67, 69 when put in place force rods 64, 66 downwardly and thereby pretension the upper support members 42, 44, 46 and hold the inner vessel securely. Member 63 is removably placed between the inner and outer vessel prior to shipment to prevent rotational and axial movement of the inner vessel 14 and radiation shield 16. Member 63 can be removed at the site by access through manway 26.

Restraining of the inner vessel is necessary because the most severe loading is encountered during shipment by rail, truck or other common carrier. Such vibrating and shock loading can cause severe damage to the inner vessel 14 if it is not properly restrained. Members 64, 66 provide the necessary restraint so that the entire container can be shipped without damage to the inner vessel 14. At destination the restraining members 63, 64, and 66 can be readily removed.

it is apparent that a container such as disclosed can be used for storing fluids other than the cryogenic fluids. t The method of removal of the cryogenic fluid and conversely filling of the container can be of any known type and forms no part of this invention.

Having thus described my invention by reference to a preferred embodiment, I wish it understood that it is to be limited in scope only to be defined in the appended claims.

lclaim:

1. In a stationary double-walled container for storing fluids at other than ambient temperature wherein the double-wall consists of an outer cylindrical vessel and an inner cylindrical vessel held in spaced-apart relation with their principal axes horizontal the improvement which comprises:

means for restraining one end of the inner vessel frommovement relative to the other end of the inner vessel, said means comprising a plurality of elongate tension members said tension members comprising a first pair of tension members one end of each member being secured to the upper inner surface of the outer vessel and the other'end of each member secured to a receiving member on the outer surface of the inner vessel, each of said pair of members being disposed at an angle greater than 0 and less than to a vertical plane containing the principal axis of the container and a second pair of tension members angularly related to each other as said first pair of tension members in a plane generally horizontal rigidly secured at a first end to the inner surface of the outer vessel end wall and at the other end to the outer surface of the corresponding end wall of the inner vessel; means supporting the unrestrained end of the inner vessel, said means including a third pair of elongate tension members in'an angular relationship similar to that of said first pair of tension numbers has been inserted pivotally mounted on the outer vessel to permit the unrestrained end of the inner vessel to move relative to the restrained end when the temperature of the inner vessel changes; and at least two temporary members forcibly inserted between said inner vessel and said outer vessel 'for rigidly securing the inner vessel and the outer vessel in spaced relationship to prevent damage of the container during shipment to destination, said rigid securing members readily removablefrom outside the outer vessel.

2. A container according to claim 1 wherein a radiation shield is disposed between said inner and outer vessels.

3. A generally cylindrical cryogenic storage tank disposed with its principal axis horizontal comprising in combination:

an inner vessel adapted to receive a charge of a cryogenic fluid; an outer vessel spaced apart from and completely surrounding the inner vessel;

the inner vessel being positioned within the outer vessel by a plurality of supports affixed to the outer shell so that the supports are subject only to tension stresses induced by the weight of the inner vessel and the charge of cryogenic fluid;

said supports comprising at one end of the inner vessel a first pair of elongated tension members with one end of each member being secured to the upper inner surface of the outer vessel and the other end of each member secured to a receiving member on the outer surface of the inner vessel, each of said pair of members being disposed at an angle greater than 0 and less than 90 to a vertical plane containing the principal axis of the storage tank, a second pair of tension members angularly related to each other as said first pair of tension gate tension members in an angular relationship similar to that of said first pair of tension members pivotally mounted on the outer vessel to permit the unrestrained end of the inner vessel to move relative to the restrained end when the temperature of the inner vessel changes.

237g? U ITEIS STATES PATENT omcnf CERTIFICATE OF CORRECTION Patent No. 3,692,206 Dated S tember 19, 1-972 Inventofls) Cla r enoe J Hornbeck It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column line 29 the word "numbers? should read --members--.

Column l, line 30, the words "has been inserted" should be de leted.

Signed and sealed 'this 3rd day of December 1974.

(SEAL) Atteat: v

McCOY M. GIBSON, JR... C. MARSHALL DANN Attesting Officer; Conmissionet of Patents 

1. In a stationary double-walled container for storing fluids at other than ambient temperature wherein the double-wall consists of an outer cylindrical vessel and an inner cylindrical vessel held in spaced-apart relation with their principal axes horizontal the improvement which comprises: means for restraining one end of the inner vessel from movement relative to the other end of the inner vessel, said means comprising a plurality of elongate tension members said tension members comprising a first pair of tension members one end of each member being secured to the upper inner surface of the outer vessel and the other end of each member secured to a receiving member on the outer surface of the inner vessel, each of said pair of members being disposed at an angle greater than 0* and less than 90* to a vertical plane containing the principal axis of the container and a second pair of tension members angularly related to each other as said first pair of tension members in a plane generally horizontal rigidly secured at a first end to the inner surface of the outer vessel end wall and at the other end to the outer surface of the corresponding end wall of the inner vessel; means supporting the unrestrained end of the inner vessel, said means including a third pair of elongate tension members in an angular relationship similar to that of said first pair of tension numbers has been inserted pivotally mounted on the outer vessel to permit the unrestrained end of the inner vessel to move relative to the restrained end when the temperature of the inner vessel changes; and at least two temporary members forcibly inserted between said inner vessel and said outer vessel for rigidly securing the inner vessel and the outer vessel in spaced relationship to prevent damage of the container during shipment to destination, said rigid securing members readily removable from outside the outer vessel.
 2. A container according to claim 1 wherein a radiation shield is disposed between said inner and outer vessels.
 3. A generally cylindrical cryogenic storage tank disposed with its principal axis horizontal comprising in combination: an inner vessel adapted to receive a charge of a cryogenic fluid; an outer vessel spaced apart from and completely surrounding the inner vessel; the inner vessel being positioned within the outer vessel by a plurality of supports affixed to the outer shell so that the supports are subject only to tension stresses induced by the weight of the inner vessel and the charge of cryogenic fluid; said supports comprising at one end of the inner vessel a first pair of elongated tension members with one end of each member being secured to the upper inner surface of the outer vessel and the other end of each member secured to a receiving member on the outer surface of the inner vessel, each of said pair of members being disposed at an angle greater than 0* and less than 90* to a vertical plane containing the principal axis of the storage tank, a second pair of tension members angularly related to each other as said first pair of tension members in a generally horizontal plane rigidly secured at a first end to the inner surface of the outer vessel end wall and at the other end to the outer surface of the corresponding end wall of the inner vessel; and means supporting the unrestrained end of the inner vessel, said means including a third pair of elongate tension members in an angular relationship similar to that of said first pair of tension members pivotally mounted on the outer vessel to permit the unrestrained end of the inner vessel to move relative to the restrained end when the temperature of the inner vessel changes. 